How a gnusb can make another one.

This turns the gnusb into a full fledged AVR programmer that can be used to reprogram any ATMEL AVR microcontroller through avrdude. The above firmware makes the gnusb behave like it’s a USBasp from fischl.de – in fact it’s the original USBasp firmware with just some minor modifications to adapt to gnusb’s hardware layout.

(The gnusb bootloader acts the same, it also masquerades as USBasp but it reprograms one’s gnusb internal EEPROM. The gnusbASP – AVR Programmer above acts as a real SPI programmer for other devices. It really toggles the bits on the gnusbs physical output ports)

I use the following adapter cable that plugs into a gnusb’s PORTB and can be used to fuse and flash another virgin atmega16 with the gnusb bootloader and firmware, thus reproducing a new gnusb…